Dental chair



A. J. MAY

DENTAL CHAIR Sept; 13, 1927.

Filed April 11. 1924 I 6 Sheets-Sheet l .Za anz BY ATTORNEY Sept. 13, 1927.

A. J. MAY DEN AL CHAIR Filed April '11. 1924 6 Sheet-Sheet s Sept. 13, 1927.

A, J. MAY

DENTAL CHAIR 6 Sheets-Sheet 4 Filed April 11-, 1924 INVENTORQ Ar a; (0 D Sept. 13,1927. A J MAY 1,642,258

DENTAL CHAIR Filed April 11. 1924 6 Sheets-Sheet 5 a a w, m P 4 rhnnnnnnn i I INVENTOR. 4/ 17y uls- ATTORNEY 1,642,258 Sept. 13, 1927. A. J. MAY I DENTAL CHAIR Filed vApril 11, 1924 6 Sheets- Sheet 6 moving Figure 5.

Patent ed Sept.13, 1 927.

UNITED i STATES PATENT: orrlcs.

man J. KAY, or nocnns'rna, new YORK,- assrenoa ro-arrrnn DENTAL- MANUFAC- TURING .00., OI' BOCHE STEIB, NEW YORK, A CORPORATION 01' NEW YORK.

DENTAL ennui.

Application fled April 11, 1s24.- Serial No. 705,738.

This invention relates to improvements in dental chairs, and has for its object to provide a practical and simply operated chair. A further object of the Invention is to provide a chair of this kind with simple motor driven means for elevating the telescoping sections. A still further'object ofthe invention is to" provide improved means for and controlling the movements of the telescoping sep'tions. To these and other ends the invention consists in certain improvementsand combinations of parts all as will .be hereinafter more fully described, the

novel features bein pointed out in the' claims at the end of t is specification.

In the drawings:

Figure 1 is a vertical sectional view through the base of a dental chair constructed according to my invention and showing'the assembled parts in their lower-' most position; 1

Figure 2 is a similar view at substantially right'angles to that of-Figure 1 and showing. the motor driven devices for actuating. the telescoping parts.

Figure 3 is 'a view similar to Figure 2 but showingthe parts in difierentpositions.

Figure 4 is a horizontal sectional view taken substantially on the line Pi-4* of Figure 2.

Figure 5 is a side elevation of the'devices mounted on the base within the innermovable section.

Figure 6 is a plan view of the same;

Figure 7 is a section on the line 7 of Figure 8 is a section on the line 8"8" of Figure 5. I Y

Figure 9 is a side elevation of a portion of the base, parts being broken away to ex pose the underlying parts. v

Figure 10 is a horizontal section through the base and shows the connections between the drivin andv driven members and means for contro ling the same.

Figures 11", 12, 13, 14, 15 and 16 are detail views showing a simple form of clutch mechanism for controlling the operation of the elevating devices.

Similar reference numerals throughout the several views indicate the same parts.

Referring to the drawings, I have shown a hollow base member 1 in which the telescopingv members are mounted or housed. The member 1 may be closed at its bottom if desired, and is open at the top as shown. It is substantially circular in cross section and has a central circular depression in its bottom wall 2. 'Arran ed to move vertically within the casing or seated in the depression in its'bottom is an outer telescoping section 3, within which is movably mounted an inner telescoping sec-' tion 4. Each of said sections are hollow and open at both the top and bottom, the inner section 4 being closed at its open upper end.

by a chair seat frame 5 of any usual or rease 1 and normally ferred construction, which is journale in the upper cylindrical end of said section to rotate thereon, as well understood in the art.

Means are provided for guiding the telescopferentplanes in the base member. Each set of these rollers comprises two pairs, see Figure 4, arran ed diametrically opposite each sections in their vertical movement s.-. Sa d means for the outer section comprises two sets of rollers 6 and 7 arranged in difother, and t e rollers of each pair are arranged at substantially right angles to each other and are journaled in lugs or ears 8 pro jecting from the inner wall of the casing 1..

The rollers of each pair engage the angularly arranged sides of vertically extending tracks 9 and 10 on the outer section 3. By'this ar-w rangement it willbe noted that the rollers of each pair oppose each other and that. each set of rollers comprises two'pairs opposin each other to efl'ectively. prevent latera movements of the section and insure steady even movements thereof. 1 The inner telescoping section 4 is similarly mounted in the outer section, as will be seen by reference to Figures 3 and 4. Two sets ofrollers 12 and '13 beingprovided and arranged in .difi'erent vertical planes, each-set comprising two pairs of diametrically arranged rollers journaled at substantially ri ht angles to each other in projections 14 on t e inner wall of the outer member 3. Each pair 'of' o posing rollers of the set engages opposed si es of a vertical ioo rail or track on the outer'wall of 'theinnerQ I section 4. Mechanical means are provided .for elevating the outer member 3 and for simultaneously elevating the innermembe'g on bar is carried. To this end there is mounted the outer member by which the inner meme I member 4 when the latter is in its normal depressed position. The standard 16 is constructed with two opposing parts 18 and 19, see Fig. 8, forming opposed guideways or tracks 20 and 21 between them in which are mounted the vertical toothed members or racks 22 and 23 adapted to reciprocate vertically in theguideways. When innormal de ressed position the racks do not extend qulte to the plane of the upper surface of the base 2 and at their lower extremities are provided with outwardly extending lugs or projections 24 and 25 which terminate in open slots 26 and 27 in the lower end of the inner telescoping member 4 and at their outer ends may be provided with tapered openings for the reception of screws 28 by means of which in-the present instance the racks are secured to the outer telescoping member 3 as clearly shown in Fig. 1. At their upper ends, the parts 18 and 19 are united by a part 29 in the form of a head. having a central vertical bearing openin for a purpose presently to be described. ecured toopposite sides of the part 29 by any suitable means, as by the bolts 30, are the members or plates 31 forming with the head, bearing openings for the racks 22 and 23 and in which the racks have a sliding movement. The plates 31 rise vertically above the head 29 and have a block 32 s'oaced vertically from the head 29 supported between them by means of the bolts 33. Arranged on opposite sides of the racks 22 and 23 and between the head 29 and block 32 and having bearings in the plates 31 are the substantially parallel shafts 34 and 35. Eachof the shafts 34 and 35 has a pair of gears 36 mounted thereon to turn therewith and meshing with teeth 37 pro the shafts 34 and 35 are rotated by the worm 39 they revolve in opposite directions to either elevate or depress the racks 22 and 23 simultaneously at a uniform speed and that the outer telescoping member 3 which is secured to the racks is also elevated or depressed.

pressing the inner member 4 relatively to the outer member when. the latter is elevated or depressed. To thisend', a member 40 in the form of a ring is secured to the upper ends of-the racks 22 and 23 by means Means are provided for elevating and de of the "screws or bolts 41 or any other suitable means. This ring serves to connect the racks to move as a unit and also carries a pair of wheels or pulleys 42 mounted in bearings 43 and 44 on opposite sides of the central opening in the .rlng. Secured to inwardly projecting lugs 45 in the inner member 4 are flexible members 46 and 47, in the present instance shown as chains, whichare led over the pulleys 42 inwardly and downwardly and anchored at their opposite ends in a projection 48 provided therefore in a plug 49 fixed in the block 32 and normally projecting through the central opening in the ring 40. From this construction, it will be noted that when the racks 22 and 23are elevated to raise the outer section 3, thepul leys 42 are also elevated and the flexible members 46 and 47 move inwardly over the pulleys and raise the inner section to which the outer ends of the flexible members are secured.

The plug 49 is threaded into the upper end of a bushing 50 which is threaded into the central opening in the block 32. Seated in the lower end of said bushing, and having a bearing therein is the upper end of the shaft 51 to which the worm 39 is keyed or otherwise secured. The lower end of the shaft 51 is somewhat reduced in diameter and extends into an opening in the upper end of an extension 52 of said shaft to whlch it. is keyed. The parts 51 and 52 thus rotate as one and in effect combine to forma single shaft. At its lower end the member 52 is reduced in diameter and has a bearing in a central opening in the base 2. If desired a nut 53 may be threaded on the outer or lower end of the shaft and into a depression provided therefore in the base 2. Keyed on the reduced portion of the shaft 52 and arranged in the central depression in the upper surface of the base 2 is a gear wheel 54, supported to revolve on antifriction bearings as clearly shown in Fig. 1. The wheel ill) or pinion 54 meshes with an. idler 55 mounted on the base 2 and this idler in turn meshes with two gears or pinions 56 and 57 also connecting one or the other of said gears with its shaft to turn it and with it the gear 56 or 57 mounted thereon. The gears 62 and 63 have downwardly'extending portions 'antifriction ballbearings shown, if desired.

' Thecup member 64 forms one part of a friction clutch whereby the shaft is connected with the worm gear to rotate therewith. Each of the blocks 66 is sectioned away on diametrically opposite sides to spaces in each of which friction devices are mounted, and slidably held in position by uncut portions 67 on the blocks 66 on which the dogs are supported. In each of said spaces is movably mounted a pair of dogs in the form of blocks 68 having arcuate faces 68 adapted to engage the inner surface of the cup member to connect the cup member and the gear thereon to theblock 66 to rotate therewith; when, however, the blocksv are released the cup member rotates inde rpendently of the block and the shafton.

which it is mounted. The members 68 are cut away at their inner ends adjacent each other to form a rectangular space or opening 69. The dogs are 'cut away-at theirinner ends to form the inwardly projecting portions 70 of reduced thickness whlch are engaged andheld in position by the projections 67 on the block 66. Movably mounted between the projections 67 and adapted to operatively engage the inner ends of the dogs 68 is an operating member in the form of a rectangular block 72 having a stem 73 projecting downwardly between the projections 67. On its lower extremity, the member 73 is provided with an arcuate crank arm 74. It will be readily understood that there are two sets of these friction devices in each of the cup members 64 and'two crank arms 74 which extend through arcs of substantially 90 each and terminate at points substantiallydiametrically opposite each other. It will be noted that when the actuating devices 72 are positioned with their engaging sides substantially parallel with the diameter of the cup, the dogs or frictional engaging members 68are permit ted to move inwardly toward each other to disengage the cup, if however the free ends of arms 74 are moved outward the blocks 72'are turned on their. axes to engage the inner ends of the dogs 68 and move .or pry them apart and into frictional engagement with the cup members 64. 'For the purpose of actuating the arms 74 there .is mounted on each of the shafts 58 and 59 for vertical sliding movements intoand out of engagement with the free ends of the arms 74 a v hub or block 75 substantially hemispherical in form splined to the shaft 58 to rotate therewith and provided'with acircumferential groove 76 adjacent itslower end, en-

rovide aged by diametrically opposite projections 77. Theseprojections are carried at the ends of arms 78 of a yoke 79. swiveled on a rocking arm 80 pivoted intermediate its ends to a support 81. It will be understood that there are two of the hub'or actuating members one on each of the shafts 58 and 59, and two of. theyokes 79, swiveled on the .arm on opposite sides of its pivotal center and at substantially. equal distances therefrom. It will be noted that by this construction, when the arm 80 is in a substantially horizontal position, the members 75 are in a neutral position substantially as shown in Fig. 11 with neither of the clutching devices in engaging position. At this time, the gears 62 and 63 may rotate freely is moved on its pivot from this neutral po- -on their shafts. When however, the bar 80 I moves into engagement with the ends of the arms 74 to actuate the corresponding clutch ing devices to turn the shaft 58 or 59 to actuate the devices for elevating or depressing the telescoping members. If desired, the

'inner'engaging ends of the arms 74 may be provided with antifriction bearings 82, as shown in the drawings.

Means, under control ofthe operator, are provided for rocking the arm 80 in one direction or the other. Said means comprises an arm or extension 83, Fig. 9,'secured to one end of the armand extending upwardly therefrom. To the upper end of the extension 83is pivotallyconnected an-arm 84 of a bell crank lever 85 pivotally mounted in the supports 86 projecting from the bottom 2 of the base section. The other arm 87' of 'the bell crank extends downwardly from the pivot and at its lower end is pivoted to the end of a rod or link 88. At its other end, the rod 88 is pivoted in ears 89 projecting from a'rock shaft 90 mounted in projections 91 on the bottom 2. Extending in opposite directions from the rock shaft 90 are arms 92 and 93 and extending upwardly from the ends of said arms and through openingsprov'ided therefor in the base section, are operating members 94-and 95 having their upper outer ends offset laterally and enlarged as at 96 and 97 to be engaged and operated conveniently by the foot of the operator. To retain the parts in normal neutral position, expansion springs 98 and 99 may be coiled about the members 94 and 95 between the arms 92 and 93 and the wall of the base section. From thisconstruction', it will be noted that when the arm 92 is-depressed, the arm 84 of the bell crank 85 will swing downwardly to depress the adjacent end of the rock arm 80 and elevate the opposite end to actuatethe dlutch devices to connect the gear 63 to the shaft 59'. When however the arm 93 is depressed, the arm 84 of the bell crank is elevated ancL also the adjacent end of the rocking arm 80 to actuate the clutch devlces to connect the gear 62 to the shaft 58 to rotate the same. When released the .parts will be returned to the automatically closing the circuit of the motor when either clutch is actuated to rotate a shaft 58 or 59. Said means comprises a pivoted switch member 101 movable from a normal central rpm-a1 position shown in Flg. 9 into engag nent with one or the other of the contact members 1.02 and 103, said switch having constant sliding engagement with the contact'member 104. Mounted on the arm 84 of the bell crank is a link 105 loosely connecting said arm with an arm 106 connected with the switch 101 and projecting from its pivot. When the arm 84 is elevated the switch 101 is moved to the right into engagement with the contact 102 to close .the circuit through the contacts 104 and 102 and when the arm 84 is depressed the switch 101 is moved to the left into engagement with the contact 103 to close the circuit through the contacts 104 and- 103. From an inspection of the drawings it will be noted that rotation of the worm 64 operates to turn the gears58 and 59 in opposite directions,

which motion is transmitted to the gears 56' and 57 through the operation of the clutch devices and to the gear 54 through the. gear 55. The gear 54'being rotated in one direction or the other to elevate or depress the telescoping sections through the gears 34 and 35 as one or the other of the clutches is thrown into operation to turn the gear 56.

. or the gear 57 in the reverse direction,

Means are provided for automaticallyrturning the parts to normal neutral position when the outer telescoping member approaches the extreme of its movement in either direction. Said means comprises a rod 107 having a saddle 108 at its lower end provided with an inclined slot 109. The saddle 108 is arranged on the. rod 88 which has a pin 110 projecting into the inclined slot 'in the. saddle. At its upper end, the

rod 107 is enlarged as at 111 and slidably fits in an eye 112 projecting from the wall. 1 of the outer telescoping member.

rod 88 is moved to the right in Fig. 9,-thc clutch devices are thrown into operation to i drive the shaft 59 and gear 57 to elevate the edges of the slot 109 operating on "the pin When the 110 to cam the rod 88 to the left in Fig. 9 to return the parts to normal neutral position. When the 'rod 88 is moved to the left to reverse the operation, the eye or ring 112 rides down the rod 107 asthe telescoping sections are'depressed until the limit of their downward movement-is approached when a lug 113 projecting from the outer telescoping member engages the upper end of the rod 107 and depresses it. This action cams the rod .88 to the right and again returns the parts to normal neutral position. With theparts in the potition shown in Fig. 9 in which the telescoping members are in depressed position the bar 88 is locked against movement to the left and the pedal 97 against depression to start the motor and close the clutch to actuate the parts to further depress the telescoping members through the engagement of the rod 107 with the lug or stop .113. Similarly when the motor when in elet'iated position theinner.

teleicoping member 4 is supported on the outer member 3- by means of the flexible members 46 and '47 and the outermember 3 is supported on the racks22 and 23 and actuating devices therefore. j

I claim as my invention:

1. In a chair base, the combination of a base member, inner and outer telescoping -members movable therein, rack and pinion devices operating within the telescoping members to elevate or to depress the same, a

standard projecting within the inner telescoping member and forming a support forthe pinion and a guide for the rack, motor driven means for actuating sald rack and pinion devices, an operating COIIIIGCtlOIlbetween the. standard and inner telescoping member and me us for controlling said motor driven means 1 2. In a chair ase the combination of a base member, a standard projecting lon tudinallywithin .the basemember, a .te escoping member movable within the base member, a rack projecting within and guidtelescoping member and adapted to raise the latter, a 'pinion engaging said rack, motor driven means for actuating said pinion, a second'telescoping'member within the first and a'fiexible operating connection having ed'by said standard and connected with said member.

one end connected with the standard and the other with the second mentioned telescoping 3. In a chair base, the combination of a base member, a telescoping member movable therein, a rack disposed within and connected with said, telescoping member adapted to raisethe latter,a pinion engaging said rack,

v a standard projecting longitudinally within Y therein, a standard projecting longitudinally within the telescoping member, a rack movable upon the standard and having teeth on rack and operative to move the rack longiopposite edges thereof and being disposed within and connected with said telescopin member, pinions engaging the teeth of sai tudinally withiir the base, motor driven means for actuatin said pinions, and means for controlling sai motor driven means;

5. In a chair base, the combination of a base member, a telescoping member movable therein, a standard projecting longitudinally within the elescopin member, a pair of racks movab e upon t e standard and having ,0 positely arranged teeth-and being dispose within and connected with said telescoping member, a pair of pinions engaging each rack, a pair of shafts revolubly supported on the base member on each of which a pinion of each pair is mounted, motor dr1ven means for driving said shafts, and

means for controlling said motor driven means. v

6. In a chair base, the combination of a basemember, a telescoping member movable therein, a pair of racks disposed within and N connected with said telescoping member for raising the latter, a standard on the base 4 member within the telescoping member having guides in which said racks are movable, pinions enga ing-said racks, shafts revoluble 1n said stan ard and carrying said pinions, motor driven means comprising a worm and geari for driving said shafts and means for controlling said motor driven means.

7. Ina chair. base, the combination of a base section, an outer telescoping section within the inner telesco ing sect-ion and be-,

ing secured thereto an to a fixed support within the inner section at its opposite end and apulley disposed within the inner section and means for moving the inner tele- .ter, and means operatively connected with outer telescoping sectiommeans formoving the outer telescoping section onthe base secscoping section relatively to the outer section t when thelatter is moved, said means comprising a pair of flexible members each; terminatmg at one end within the inner telescoping section and beingusecured thereto an to a fixed support wit n the inner sec-' tion at its 0 posite end and a pairof pul. leys'disposed within the inner section and movable with the outer section and over which the flexible members move.

9. In a chair base, the combination of a base section, anouter telescoping section movable therein, an inner telescoping section movable in the outerftelescoping section, means for moving the inner section relatively to the outer section when the latter is moved, and motor driven means for moving the outer section, said means comprisin a pair of movable racks rigidly "connected with the outer. section for moving the. latter and normally arranged within the inner section and being disposed independently therev so of to move relative thereto, pinions enga' ing said racks and driving means for t e pinions. p v

10; In a chair base, the combination of a base section, an outer telescoping section movable. therein, an inner telescoping section movable in'the outer telescoping section, means for moving the inner section relativel to the outer section when the latter is move a standard normall projecting into the in-' ner section from t e base, a pair of connected racks movable in said standard and connected with the outer section, plmons rev oluble in said standardand enga ing said racks to move the outer'section, an a worms,

for driving said pinionsv arranged on a ver tical axis in said standard;

' 11. In a chair lift mechanism, the combination of a base, a columnv mounted for movement upon the base, a support within the base projecting within the column, a rack slidably mounted upon the support and connected with the column to move the lat- :20 the rack including a pinion and a shutter:- tending longitudinally within the column and having a gear adapted to drive the pinion. 1

12-. In a chair lift mechanism, the combination of a base, a column mounted for movement u on the base, a sup ort extend ing longitu inally within the ase, a rack slidably mounted upon said support and operatively connected with the'column, a 130 pinion carried by said sup ort and en aging the rack, a shaft dispos zad longitudinally within the support and operatively connected with the pinion, and operating means for the shaft.

13. In a chair lift mechanism, the combination of a base, a 'column mounted for movement upon the base, a standard within,

' iournaled upon the standard having pinions meshing ith the racks, a gear upon said shaft, and a drive shaft operatively connected with said gear.

15. In a chair lift mechanism, the combination of a base, a column mounted for movement upon the base, a second column movable relatively to the first, a fixed support within the base, a rack slidably mounted upon said support and operatively connected with the first mentioned column, means actuated by the rack adapted to move the second column relatively to the first, and means operatively connected with the rack.

16. In a chair lift mechanism, the c0mbination of a base, an outer section mounted for movement upon the base, an inner section, a track supported within the inner section, a rack slidable upon the track and operatively connected both with the inner and outer sections for moving one relative to another, and means operatively connected with the rack.

17. In a chair lift mechanism, the combination of a base, a column mounted for movement upon the base, a second column movable ,relative to the first, a fixed support projecting within the first mentioned column, a vflexible connection between the sup ort and the second mentioned column, a device movable vertically upon the support and adapted to raise the first vmentioned column and also arranged to cooperate with said flexible. member to raise the second men- .said flexible connections wherelg' 18. In a chair 11ft mechanism, the com bination of a base, a column movable within.

the base, a second column movable-within the first, .a"standard projecting upwardly within the base, a flexible connection between the standard and second mentioned column, a rack slidably mounted upon the standard and operatively connected with the first mentionedcolumn, means carried by the rack adapted to engage said flexible connec-' tion whereby to ralse the second mentioned column, and means for actuating the rack.

19. In a chair lift mechanism, the combination of a base, a column mounted for movement upon the base, a second column movable within the first, a standard projecting upwardly within the base, a pair of flexible connections between the standard and the second mentioned column, a pair of racks slidably disposed upon said standard, pulleys carried by said racks and engaging to move the second mentioned column, an operating means for the racks.

20. In a chair lift mechanism, the combination of a base, a column movable therein, a second column mounted for movement within the first, a standard'projecting upwardly within the base, slidably mounted means upon the standard connected with the first mentioned column for moving the latter, means operatively connecting said slidably mounted means with the second mentioned column, and a shaft projecting within the base and operatively connected with said slidably mounted means. f

21. In a chair lift mechanism, the-combination of a base, a column movable therein, a second column movable within the first, a standard projecting upwardly within the base into said columns when the latter are in lowered position, a member slidably mounted upon the standard and operatively connecte with the first mentioned column, means inter osed between the standard vand the second mentioned column with which said slidably mounted members is adapted to co 0 erate whereby to move the second mentloned column,- and means for actuating said and gearing driven thereby.

ADAM J. MAY. 

